Retrofit response codes with RxJava2

Question

So I wanted to implement the example of response from the API like in this video droidcon NYC 2017 - Advanced Networking with RxJava + Retrofit

And this is my code:

Presenter.java

compositeDisposable.add(RetrofitClient.createService(GetApi.class)
            .getResponseFromServer(token)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new Consumer<ResponseFromServer>() {
                @Override
                public void accept(ResponseFromServer responseFromServer) throws Exception {
                    mView.setResponseObject(responseFromServer);
                }
            }, new Consumer<Throwable>() {
                @Override
                public void accept(Throwable throwable) throws Exception {
                    throwable.printStackTrace();
                    if (throwable instanceof HttpException) {
                        int responseCode = ((HttpException) throwable).code();
                    }

                }
            }));

So here, when I get some 4xx error response from the server, I can go to Throwable and get the response code, and if response is okay I can get my object, and everything is cool.

However, in the video example above, the guy suggest that I wrap my ResponseFromServer with Response like this: Single<Response<ResponseFromServer>> getResponseFromServer(@Header("X-Authorize") String token); so I can access response codes also, but in that case, my Throwable never gets called, so I can access to the codes only in the first accept method, but in the video he catch the errors in the Throwable section. So, I cant figure it out what I'm doing wrong? Maybe I'm using the wrong Observer?

Answer 1

When Response from Server is code < 200 || code >= 300 code < 200 || code >= 300 in those cases onError() will be invoked. and other cases onNext() will invoke.

Also, If your code from onNext() throws any exception, that will be catch in onError()

Answer 2

I think i figured it out, if we wrap our response object with Observable<Response<Object>> all of the response code will be caught in the regular accept method, so we kinda need to extract the codes manually and do the checks. However, if we keep the Observable<Object> , errorCode < 200 || errorCode > 400 will be caught in the onError method.